kernel/irq/chip.c

   1 /*
   2  * linux/kernel/irq/chip.c
   3  *
   4  * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar
   5  * Copyright (C) 2005-2006, Thomas Gleixner, Russell King
   6  *
   7  * This file contains the core interrupt handling code, for irq-chip
   8  * based architectures.
   9  *
  10  * Detailed information is available in Documentation/DocBook/genericirq
  11  */
  12
  13 #include <linux/irq.h>
  14 #include <linux/msi.h>
  15 #include <linux/module.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel_stat.h>
  18
  19 #include "internals.h"
  20
  21 static void dynamic_irq_init_x(unsigned int irq, bool keep_chip_data)
  22 {
  23         struct irq_desc *desc;
  24         unsigned long flags;
  25
  26         desc = irq_to_desc(irq);
  27         if (!desc) {
  28                 WARN(1, KERN_ERR "Trying to initialize invalid IRQ%d\n", irq);
  29                 return;
  30         }
  31
  32         /* Ensure we don't have left over values from a previous use of this irq */
  33         raw_spin_lock_irqsave(&desc->lock, flags);
  34         desc->status = IRQ_DISABLED;
  35         desc->chip = &no_irq_chip;
  36         desc->handle_irq = handle_bad_irq;
  37         desc->depth = 1;
  38         desc->msi_desc = NULL;
  39         desc->handler_data = NULL;
  40         if (!keep_chip_data)
  41                 desc->chip_data = NULL;
  42         desc->action = NULL;
  43         desc->irq_count = 0;
  44         desc->irqs_unhandled = 0;
  45 #ifdef CONFIG_SMP
  46         cpumask_setall(desc->affinity);
  47 #ifdef CONFIG_GENERIC_PENDING_IRQ
  48         cpumask_clear(desc->pending_mask);
  49 #endif
  50 #endif
  51         raw_spin_unlock_irqrestore(&desc->lock, flags);
  52 }
  53
  54 /**
  55  *      dynamic_irq_init - initialize a dynamically allocated irq
  56  *      @irq:   irq number to initialize
  57  */
  58 void dynamic_irq_init(unsigned int irq)
  59 {
  60         dynamic_irq_init_x(irq, false);
  61 }
  62
  63 /**
  64  *      dynamic_irq_init_keep_chip_data - initialize a dynamically allocated irq
  65  *      @irq:   irq number to initialize
  66  *
  67  *      does not set irq_to_desc(irq)->chip_data to NULL
  68  */
  69 void dynamic_irq_init_keep_chip_data(unsigned int irq)
  70 {
  71         dynamic_irq_init_x(irq, true);
  72 }
  73
  74 static void dynamic_irq_cleanup_x(unsigned int irq, bool keep_chip_data)
  75 {
  76         struct irq_desc *desc = irq_to_desc(irq);
  77         unsigned long flags;
  78
  79         if (!desc) {
  80                 WARN(1, KERN_ERR "Trying to cleanup invalid IRQ%d\n", irq);
  81                 return;
  82         }
  83
  84         raw_spin_lock_irqsave(&desc->lock, flags);
  85         if (desc->action) {
  86                 raw_spin_unlock_irqrestore(&desc->lock, flags);
  87                 WARN(1, KERN_ERR "Destroying IRQ%d without calling free_irq\n",
  88                         irq);
  89                 return;
  90         }
  91         desc->msi_desc = NULL;
  92         desc->handler_data = NULL;
  93         if (!keep_chip_data)
  94                 desc->chip_data = NULL;
  95         desc->handle_irq = handle_bad_irq;
  96         desc->chip = &no_irq_chip;
  97         desc->name = NULL;
  98         clear_kstat_irqs(desc);
  99         raw_spin_unlock_irqrestore(&desc->lock, flags);
 100 }
 101
 102 /**
 103  *      dynamic_irq_cleanup - cleanup a dynamically allocated irq
 104  *      @irq:   irq number to initialize
 105  */
 106 void dynamic_irq_cleanup(unsigned int irq)
 107 {
 108         dynamic_irq_cleanup_x(irq, false);
 109 }
 110
 111 /**
 112  *      dynamic_irq_cleanup_keep_chip_data - cleanup a dynamically allocated irq
 113  *      @irq:   irq number to initialize
 114  *
 115  *      does not set irq_to_desc(irq)->chip_data to NULL
 116  */
 117 void dynamic_irq_cleanup_keep_chip_data(unsigned int irq)
 118 {
 119         dynamic_irq_cleanup_x(irq, true);
 120 }
 121
 122
 123 /**
 124  *      set_irq_chip - set the irq chip for an irq
 125  *      @irq:   irq number
 126  *      @chip:  pointer to irq chip description structure
 127  */
 128 int set_irq_chip(unsigned int irq, struct irq_chip *chip)
 129 {
 130         struct irq_desc *desc = irq_to_desc(irq);
 131         unsigned long flags;
 132
 133         if (!desc) {
 134                 WARN(1, KERN_ERR "Trying to install chip for IRQ%d\n", irq);
 135                 return -EINVAL;
 136         }
 137
 138         if (!chip)
 139                 chip = &no_irq_chip;
 140
 141         raw_spin_lock_irqsave(&desc->lock, flags);
 142         irq_chip_set_defaults(chip);
 143         desc->chip = chip;
 144         raw_spin_unlock_irqrestore(&desc->lock, flags);
 145
 146         return 0;
 147 }
 148 EXPORT_SYMBOL(set_irq_chip);
 149
 150 /**
 151  *      set_irq_type - set the irq trigger type for an irq
 152  *      @irq:   irq number
 153  *      @type:  IRQ_TYPE_{LEVEL,EDGE}_* value - see include/linux/irq.h
 154  */
 155 int set_irq_type(unsigned int irq, unsigned int type)
 156 {
 157         struct irq_desc *desc = irq_to_desc(irq);
 158         unsigned long flags;
 159         int ret = -ENXIO;
 160
 161         if (!desc) {
 162                 printk(KERN_ERR "Trying to set irq type for IRQ%d\n", irq);
 163                 return -ENODEV;
 164         }
 165
 166         type &= IRQ_TYPE_SENSE_MASK;
 167         if (type == IRQ_TYPE_NONE)
 168                 return 0;
 169
 170         raw_spin_lock_irqsave(&desc->lock, flags);
 171         ret = __irq_set_trigger(desc, irq, type);
 172         raw_spin_unlock_irqrestore(&desc->lock, flags);
 173         return ret;
 174 }
 175 EXPORT_SYMBOL(set_irq_type);
 176
 177 /**
 178  *      set_irq_data - set irq type data for an irq
 179  *      @irq:   Interrupt number
 180  *      @data:  Pointer to interrupt specific data
 181  *
 182  *      Set the hardware irq controller data for an irq
 183  */
 184 int set_irq_data(unsigned int irq, void *data)
 185 {
 186         struct irq_desc *desc = irq_to_desc(irq);
 187         unsigned long flags;
 188
 189         if (!desc) {
 190                 printk(KERN_ERR
 191                        "Trying to install controller data for IRQ%d\n", irq);
 192                 return -EINVAL;
 193         }
 194
 195         raw_spin_lock_irqsave(&desc->lock, flags);
 196         desc->handler_data = data;
 197         raw_spin_unlock_irqrestore(&desc->lock, flags);
 198         return 0;
 199 }
 200 EXPORT_SYMBOL(set_irq_data);
 201
 202 /**
 203  *      set_irq_msi - set MSI descriptor data for an irq
 204  *      @irq:   Interrupt number
 205  *      @entry: Pointer to MSI descriptor data
 206  *
 207  *      Set the MSI descriptor entry for an irq
 208  */
 209 int set_irq_msi(unsigned int irq, struct msi_desc *entry)
 210 {
 211         struct irq_desc *desc = irq_to_desc(irq);
 212         unsigned long flags;
 213
 214         if (!desc) {
 215                 printk(KERN_ERR
 216                        "Trying to install msi data for IRQ%d\n", irq);
 217                 return -EINVAL;
 218         }
 219
 220         raw_spin_lock_irqsave(&desc->lock, flags);
 221         desc->msi_desc = entry;
 222         if (entry)
 223                 entry->irq = irq;
 224         raw_spin_unlock_irqrestore(&desc->lock, flags);
 225         return 0;
 226 }
 227
 228 /**
 229  *      set_irq_chip_data - set irq chip data for an irq
 230  *      @irq:   Interrupt number
 231  *      @data:  Pointer to chip specific data
 232  *
 233  *      Set the hardware irq chip data for an irq
 234  */
 235 int set_irq_chip_data(unsigned int irq, void *data)
 236 {
 237         struct irq_desc *desc = irq_to_desc(irq);
 238         unsigned long flags;
 239
 240         if (!desc) {
 241                 printk(KERN_ERR
 242                        "Trying to install chip data for IRQ%d\n", irq);
 243                 return -EINVAL;
 244         }
 245
 246         if (!desc->chip) {
 247                 printk(KERN_ERR "BUG: bad set_irq_chip_data(IRQ#%d)\n", irq);
 248                 return -EINVAL;
 249         }
 250
 251         raw_spin_lock_irqsave(&desc->lock, flags);
 252         desc->chip_data = data;
 253         raw_spin_unlock_irqrestore(&desc->lock, flags);
 254
 255         return 0;
 256 }
 257 EXPORT_SYMBOL(set_irq_chip_data);
 258
 259 /**
 260  *      set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq
 261  *
 262  *      @irq:   Interrupt number
 263  *      @nest:  0 to clear / 1 to set the IRQ_NESTED_THREAD flag
 264  *
 265  *      The IRQ_NESTED_THREAD flag indicates that on
 266  *      request_threaded_irq() no separate interrupt thread should be
 267  *      created for the irq as the handler are called nested in the
 268  *      context of a demultiplexing interrupt handler thread.
 269  */
 270 void set_irq_nested_thread(unsigned int irq, int nest)
 271 {
 272         struct irq_desc *desc = irq_to_desc(irq);
 273         unsigned long flags;
 274
 275         if (!desc)
 276                 return;
 277
 278         raw_spin_lock_irqsave(&desc->lock, flags);
 279         if (nest)
 280                 desc->status |= IRQ_NESTED_THREAD;
 281         else
 282                 desc->status &= ~IRQ_NESTED_THREAD;
 283         raw_spin_unlock_irqrestore(&desc->lock, flags);
 284 }
 285 EXPORT_SYMBOL_GPL(set_irq_nested_thread);
 286
 287 /*
 288  * default enable function
 289  */
 290 static void default_enable(unsigned int irq)
 291 {
 292         struct irq_desc *desc = irq_to_desc(irq);
 293
 294         desc->chip->unmask(irq);
 295         desc->status &= ~IRQ_MASKED;
 296 }
 297
 298 /*
 299  * default disable function
 300  */
 301 static void default_disable(unsigned int irq)
 302 {
 303 }
 304
 305 /*
 306  * default startup function
 307  */
 308 static unsigned int default_startup(unsigned int irq)
 309 {
 310         struct irq_desc *desc = irq_to_desc(irq);
 311
 312         desc->chip->enable(irq);
 313         return 0;
 314 }
 315
 316 /*
 317  * default shutdown function
 318  */
 319 static void default_shutdown(unsigned int irq)
 320 {
 321         struct irq_desc *desc = irq_to_desc(irq);
 322
 323         desc->chip->mask(irq);
 324         desc->status |= IRQ_MASKED;
 325 }
 326
 327 /*
 328  * Fixup enable/disable function pointers
 329  */
 330 void irq_chip_set_defaults(struct irq_chip *chip)
 331 {
 332         if (!chip->enable)
 333                 chip->enable = default_enable;
 334         if (!chip->disable)
 335                 chip->disable = default_disable;
 336         if (!chip->startup)
 337                 chip->startup = default_startup;
 338         /*
 339          * We use chip->disable, when the user provided its own. When
 340          * we have default_disable set for chip->disable, then we need
 341          * to use default_shutdown, otherwise the irq line is not
 342          * disabled on free_irq():
 343          */
 344         if (!chip->shutdown)
 345                 chip->shutdown = chip->disable != default_disable ?
 346                         chip->disable : default_shutdown;
 347         if (!chip->name)
 348                 chip->name = chip->typename;
 349         if (!chip->end)
 350                 chip->end = dummy_irq_chip.end;
 351 }
 352
 353 static inline void mask_ack_irq(struct irq_desc *desc, int irq)
 354 {
 355         if (desc->chip->mask_ack)
 356                 desc->chip->mask_ack(irq);
 357         else {
 358                 desc->chip->mask(irq);
 359                 if (desc->chip->ack)
 360                         desc->chip->ack(irq);
 361         }
 362 }
 363
 364 /*
 365  *      handle_nested_irq - Handle a nested irq from a irq thread
 366  *      @irq:   the interrupt number
 367  *
 368  *      Handle interrupts which are nested into a threaded interrupt
 369  *      handler. The handler function is called inside the calling
 370  *      threads context.
 371  */
 372 void handle_nested_irq(unsigned int irq)
 373 {
 374         struct irq_desc *desc = irq_to_desc(irq);
 375         struct irqaction *action;
 376         irqreturn_t action_ret;
 377
 378         might_sleep();
 379
 380         raw_spin_lock_irq(&desc->lock);
 381
 382         kstat_incr_irqs_this_cpu(irq, desc);
 383
 384         action = desc->action;
 385         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 386                 goto out_unlock;
 387
 388         desc->status |= IRQ_INPROGRESS;
 389         raw_spin_unlock_irq(&desc->lock);
 390
 391         action_ret = action->thread_fn(action->irq, action->dev_id);
 392         if (!noirqdebug)
 393                 note_interrupt(irq, desc, action_ret);
 394
 395         raw_spin_lock_irq(&desc->lock);
 396         desc->status &= ~IRQ_INPROGRESS;
 397
 398 out_unlock:
 399         raw_spin_unlock_irq(&desc->lock);
 400 }
 401 EXPORT_SYMBOL_GPL(handle_nested_irq);
 402
 403 /**
 404  *      handle_simple_irq - Simple and software-decoded IRQs.
 405  *      @irq:   the interrupt number
 406  *      @desc:  the interrupt description structure for this irq
 407  *
 408  *      Simple interrupts are either sent from a demultiplexing interrupt
 409  *      handler or come from hardware, where no interrupt hardware control
 410  *      is necessary.
 411  *
 412  *      Note: The caller is expected to handle the ack, clear, mask and
 413  *      unmask issues if necessary.
 414  */
 415 void
 416 handle_simple_irq(unsigned int irq, struct irq_desc *desc)
 417 {
 418         struct irqaction *action;
 419         irqreturn_t action_ret;
 420
 421         raw_spin_lock(&desc->lock);
 422
 423         if (unlikely(desc->status & IRQ_INPROGRESS))
 424                 goto out_unlock;
 425         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 426         kstat_incr_irqs_this_cpu(irq, desc);
 427
 428         action = desc->action;
 429         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 430                 goto out_unlock;
 431
 432         desc->status |= IRQ_INPROGRESS;
 433         raw_spin_unlock(&desc->lock);
 434
 435         action_ret = handle_IRQ_event(irq, action);
 436         if (!noirqdebug)
 437                 note_interrupt(irq, desc, action_ret);
 438
 439         raw_spin_lock(&desc->lock);
 440         desc->status &= ~IRQ_INPROGRESS;
 441 out_unlock:
 442         raw_spin_unlock(&desc->lock);
 443 }
 444
 445 /**
 446  *      handle_level_irq - Level type irq handler
 447  *      @irq:   the interrupt number
 448  *      @desc:  the interrupt description structure for this irq
 449  *
 450  *      Level type interrupts are active as long as the hardware line has
 451  *      the active level. This may require to mask the interrupt and unmask
 452  *      it after the associated handler has acknowledged the device, so the
 453  *      interrupt line is back to inactive.
 454  */
 455 void
 456 handle_level_irq(unsigned int irq, struct irq_desc *desc)
 457 {
 458         struct irqaction *action;
 459         irqreturn_t action_ret;
 460
 461         raw_spin_lock(&desc->lock);
 462         mask_ack_irq(desc, irq);
 463
 464         if (unlikely(desc->status & IRQ_INPROGRESS))
 465                 goto out_unlock;
 466         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 467         kstat_incr_irqs_this_cpu(irq, desc);
 468
 469         /*
 470          * If its disabled or no action available
 471          * keep it masked and get out of here
 472          */
 473         action = desc->action;
 474         if (unlikely(!action || (desc->status & IRQ_DISABLED)))
 475                 goto out_unlock;
 476
 477         desc->status |= IRQ_INPROGRESS;
 478         raw_spin_unlock(&desc->lock);
 479
 480         action_ret = handle_IRQ_event(irq, action);
 481         if (!noirqdebug)
 482                 note_interrupt(irq, desc, action_ret);
 483
 484         raw_spin_lock(&desc->lock);
 485         desc->status &= ~IRQ_INPROGRESS;
 486
 487         if (unlikely(desc->status & IRQ_ONESHOT))
 488                 desc->status |= IRQ_MASKED;
 489         else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
 490                 desc->chip->unmask(irq);
 491 out_unlock:
 492         raw_spin_unlock(&desc->lock);
 493 }
 494 EXPORT_SYMBOL_GPL(handle_level_irq);
 495
 496 /**
 497  *      handle_fasteoi_irq - irq handler for transparent controllers
 498  *      @irq:   the interrupt number
 499  *      @desc:  the interrupt description structure for this irq
 500  *
 501  *      Only a single callback will be issued to the chip: an ->eoi()
 502  *      call when the interrupt has been serviced. This enables support
 503  *      for modern forms of interrupt handlers, which handle the flow
 504  *      details in hardware, transparently.
 505  */
 506 void
 507 handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc)
 508 {
 509         struct irqaction *action;
 510         irqreturn_t action_ret;
 511
 512         raw_spin_lock(&desc->lock);
 513
 514         if (unlikely(desc->status & IRQ_INPROGRESS))
 515                 goto out;
 516
 517         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 518         kstat_incr_irqs_this_cpu(irq, desc);
 519
 520         /*
 521          * If its disabled or no action available
 522          * then mask it and get out of here:
 523          */
 524         action = desc->action;
 525         if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
 526                 desc->status |= IRQ_PENDING;
 527                 if (desc->chip->mask)
 528                         desc->chip->mask(irq);
 529                 goto out;
 530         }
 531
 532         desc->status |= IRQ_INPROGRESS;
 533         desc->status &= ~IRQ_PENDING;
 534         raw_spin_unlock(&desc->lock);
 535
 536         action_ret = handle_IRQ_event(irq, action);
 537         if (!noirqdebug)
 538                 note_interrupt(irq, desc, action_ret);
 539
 540         raw_spin_lock(&desc->lock);
 541         desc->status &= ~IRQ_INPROGRESS;
 542 out:
 543         desc->chip->eoi(irq);
 544
 545         raw_spin_unlock(&desc->lock);
 546 }
 547
 548 /**
 549  *      handle_edge_irq - edge type IRQ handler
 550  *      @irq:   the interrupt number
 551  *      @desc:  the interrupt description structure for this irq
 552  *
 553  *      Interrupt occures on the falling and/or rising edge of a hardware
 554  *      signal. The occurence is latched into the irq controller hardware
 555  *      and must be acked in order to be reenabled. After the ack another
 556  *      interrupt can happen on the same source even before the first one
 557  *      is handled by the associated event handler. If this happens it
 558  *      might be necessary to disable (mask) the interrupt depending on the
 559  *      controller hardware. This requires to reenable the interrupt inside
 560  *      of the loop which handles the interrupts which have arrived while
 561  *      the handler was running. If all pending interrupts are handled, the
 562  *      loop is left.
 563  */
 564 void
 565 handle_edge_irq(unsigned int irq, struct irq_desc *desc)
 566 {
 567         raw_spin_lock(&desc->lock);
 568
 569         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 570
 571         /*
 572          * If we're currently running this IRQ, or its disabled,
 573          * we shouldn't process the IRQ. Mark it pending, handle
 574          * the necessary masking and go out
 575          */
 576         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 577                     !desc->action)) {
 578                 desc->status |= (IRQ_PENDING | IRQ_MASKED);
 579                 mask_ack_irq(desc, irq);
 580                 goto out_unlock;
 581         }
 582         kstat_incr_irqs_this_cpu(irq, desc);
 583
 584         /* Start handling the irq */
 585         if (desc->chip->ack)
 586                 desc->chip->ack(irq);
 587
 588         /* Mark the IRQ currently in progress.*/
 589         desc->status |= IRQ_INPROGRESS;
 590
 591         do {
 592                 struct irqaction *action = desc->action;
 593                 irqreturn_t action_ret;
 594
 595                 if (unlikely(!action)) {
 596                         desc->chip->mask(irq);
 597                         goto out_unlock;
 598                 }
 599
 600                 /*
 601                  * When another irq arrived while we were handling
 602                  * one, we could have masked the irq.
 603                  * Renable it, if it was not disabled in meantime.
 604                  */
 605                 if (unlikely((desc->status &
 606                                (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) ==
 607                               (IRQ_PENDING | IRQ_MASKED))) {
 608                         desc->chip->unmask(irq);
 609                         desc->status &= ~IRQ_MASKED;
 610                 }
 611
 612                 desc->status &= ~IRQ_PENDING;
 613                 raw_spin_unlock(&desc->lock);
 614                 action_ret = handle_IRQ_event(irq, action);
 615                 if (!noirqdebug)
 616                         note_interrupt(irq, desc, action_ret);
 617                 raw_spin_lock(&desc->lock);
 618
 619         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 620
 621         desc->status &= ~IRQ_INPROGRESS;
 622 out_unlock:
 623         raw_spin_unlock(&desc->lock);
 624 }
 625
 626 /**
 627  *      handle_percpu_irq - Per CPU local irq handler
 628  *      @irq:   the interrupt number
 629  *      @desc:  the interrupt description structure for this irq
 630  *
 631  *      Per CPU interrupts on SMP machines without locking requirements
 632  */
 633 void
 634 handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
 635 {
 636         irqreturn_t action_ret;
 637
 638         kstat_incr_irqs_this_cpu(irq, desc);
 639
 640         if (desc->chip->ack)
 641                 desc->chip->ack(irq);
 642
 643         action_ret = handle_IRQ_event(irq, desc->action);
 644         if (!noirqdebug)
 645                 note_interrupt(irq, desc, action_ret);
 646
 647         if (desc->chip->eoi)
 648                 desc->chip->eoi(irq);
 649 }
 650
 651 void
 652 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
 653                   const char *name)
 654 {
 655         struct irq_desc *desc = irq_to_desc(irq);
 656         unsigned long flags;
 657
 658         if (!desc) {
 659                 printk(KERN_ERR
 660                        "Trying to install type control for IRQ%d\n", irq);
 661                 return;
 662         }
 663
 664         if (!handle)
 665                 handle = handle_bad_irq;
 666         else if (desc->chip == &no_irq_chip) {
 667                 printk(KERN_WARNING "Trying to install %sinterrupt handler "
 668                        "for IRQ%d\n", is_chained ? "chained " : "", irq);
 669                 /*
 670                  * Some ARM implementations install a handler for really dumb
 671                  * interrupt hardware without setting an irq_chip. This worked
 672                  * with the ARM no_irq_chip but the check in setup_irq would
 673                  * prevent us to setup the interrupt at all. Switch it to
 674                  * dummy_irq_chip for easy transition.
 675                  */
 676                 desc->chip = &dummy_irq_chip;
 677         }
 678
 679         chip_bus_lock(irq, desc);
 680         raw_spin_lock_irqsave(&desc->lock, flags);
 681
 682         /* Uninstall? */
 683         if (handle == handle_bad_irq) {
 684                 if (desc->chip != &no_irq_chip)
 685                         mask_ack_irq(desc, irq);
 686                 desc->status |= IRQ_DISABLED;
 687                 desc->depth = 1;
 688         }
 689         desc->handle_irq = handle;
 690         desc->name = name;
 691
 692         if (handle != handle_bad_irq && is_chained) {
 693                 desc->status &= ~IRQ_DISABLED;
 694                 desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
 695                 desc->depth = 0;
 696                 desc->chip->startup(irq);
 697         }
 698         raw_spin_unlock_irqrestore(&desc->lock, flags);
 699         chip_bus_sync_unlock(irq, desc);
 700 }
 701 EXPORT_SYMBOL_GPL(__set_irq_handler);
 702
 703 void
 704 set_irq_chip_and_handler(unsigned int irq, struct irq_chip *chip,
 705                          irq_flow_handler_t handle)
 706 {
 707         set_irq_chip(irq, chip);
 708         __set_irq_handler(irq, handle, 0, NULL);
 709 }
 710
 711 void
 712 set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip,
 713                               irq_flow_handler_t handle, const char *name)
 714 {
 715         set_irq_chip(irq, chip);
 716         __set_irq_handler(irq, handle, 0, name);
 717 }
 718
 719 void __init set_irq_noprobe(unsigned int irq)
 720 {
 721         struct irq_desc *desc = irq_to_desc(irq);
 722         unsigned long flags;
 723
 724         if (!desc) {
 725                 printk(KERN_ERR "Trying to mark IRQ%d non-probeable\n", irq);
 726                 return;
 727         }
 728
 729         raw_spin_lock_irqsave(&desc->lock, flags);
 730         desc->status |= IRQ_NOPROBE;
 731         raw_spin_unlock_irqrestore(&desc->lock, flags);
 732 }
 733
 734 void __init set_irq_probe(unsigned int irq)
 735 {
 736         struct irq_desc *desc = irq_to_desc(irq);
 737         unsigned long flags;
 738
 739         if (!desc) {
 740                 printk(KERN_ERR "Trying to mark IRQ%d probeable\n", irq);
 741                 return;
 742         }
 743
 744         raw_spin_lock_irqsave(&desc->lock, flags);
 745         desc->status &= ~IRQ_NOPROBE;
 746         raw_spin_unlock_irqrestore(&desc->lock, flags);
 747 }